Calcium (Phosphate, Gluconate, and Carbonate)

Indications and Usage

  • Calcium is an alkaline earth metal, as are strontium, barium, and radium.
    • A mass effect from calcium can interfere with absorption of the other alkaline earth metals and compete for bone deposition.
    • In the event of internal contamination with radioactive strontium (Sr-90) or radium (Ra-226), generous doses of calcium preparations may be beneficial.
  • To block absorption of radium or strontium through the GI tract
    • PO dosing
      • Calcium phosphate: 1200 mg PO x 1. Give one dose within 24 hours of radionuclide intake to prevent or minimize intestinal absorption. Calcium increases urinary excretion of strontium, and phosphate decreases intestinal absorption of strontium (NCRP 65).
      • Barium sulfate: 300 g PO ASAP. To be used in conjunction with IV calcium gluconate (see below)
  • For use after absorption of radium or strontium into the body to compete for bone binding sites
    • IV dosing
      • Calcium gluconate: 500 mg of calcium/ampoule: 5 ampoules in 500 cc 5% dextrose in water (D5W IV over 4-6 hours. Can be given daily for up to 6 consecutive days.
    • PO dosing
      • Calcium carbonate (e.g., Titralac® and TUMS®): Take as directed on label. Begin therapy within 12 hours of radionuclide intake

FDA Product Safety Info

  • Not FDA approved for this indication/off-label use

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  1. Management of Persons Contaminated with Radionuclides: Handbook (NCRP Report No. 161, Vol. I), National Council on Radiation Protection and Measurements, Bethesda, MD, 2008, Table 12.18 (p. 225) and Table 12.19 (p. 227). [Note: NCRP 161 supersedes NCRP 65.]